The invention relates to a trocar mandrel.
Trocar mandrels of this kind are in widespread use in minimally invasive surgery and are known, for example, from the catalogue Laparoskopie [Laparoscopy], 3rd edition 2/99, page TROC 20 B, from Karl Storz GmbH & Co KG, Tuttlingen, Germany.
A trocar is composed of a trocar sleeve and of a trocar mandrel that is to be pushed into the latter. The trocar mandrel is dimensioned such that it fills the interior of the trocar sleeve, and such that its tip extends distally beyond the trocar sleeve. It is known to give the tip of the trocar mandrel different geometries, for example a blunt tip, a conical tip or a three-edged tip.
The assembled device made up of trocar sleeve and trocar mandrel, i.e. the trocar, is used to create an access to an internal cavity of the body in minimally invasive surgery.
A widespread area of application is laparoscopy.
In laparoscopy, an incision measuring approximately 1 to 2 cm in length is made in the skin of the abdominal wall. The trocar is applied to this incision via the tip of the trocar mandrel protruding from the trocar sleeve. The assembled device is then pushed through the abdominal wall until the distal end of the device protrudes into the abdominal space. The trocar mandrel is then withdrawn and discarded.
The hollow trocar sleeve now engages in the body, for example in the abdominal wall, and a minimally invasive intervention can then be performed through the trocar sleeve.
The external diameter of a trocar sleeve is up to about 25 mm, such that the space for passing instruments through the trocar sleeve is relatively small.
In minimally invasive interventions, it has become customary, particularly in laparoscopy, to apply several such trocar sleeves. In this way, different medical instruments can then be inserted through the several trocar sleeves, for example instruments having purely a monitoring purpose, e.g. endoscopes, and medical working instruments, such as forceps, scissors, punches and the like, and also instruments for supplying media, for example gaseous media for inflating the abdominal space, or irrigation liquids for flushing blood, in particular, from the operating site.
In a number of operating techniques, it has been found to be expedient for two adjacent trocars to be inserted at a very defined distance from each other into the body. This is especially the case when a monitoring instrument pushed through a first trocar sleeve is intended to specifically monitor the working area of another instrument that is pushed through a second trocar sleeve.
The operator needs to have considerable experience to apply two or more trocars at an exactly defined distance from each other.
It is, therefore, an object of the present invention to provide a trocar system allowing to set several trocars at defined distances.